Smith grew up in New Jersey, the son of Burlington attorney Louis Smith and his wife Carol, a clinical social worker.

He worked as a founding editor of the magazine P.O.V. and editor-in-chief of its sister publication, Egg, as well as an editor of Might magazine with Dave Eggers. He was also managing editor of the news service AlterNet. and editor of the city guide network, Boulevards.

Smith also worked as executive editor of Yahoo! Internet Life, senior editor at ESPN The Magazine, and articles editor at Men's Journal. His writing has appeared in The New York Times, Popular Science, Men’s Health, Salon, Slate, and other places.

In 2004, Smith's wife, Piper Kerman, a graduate of Smith College, had the unlikely experience during their engagement of serving a 15-month sentence at the Federal Correctional Institution, Danbury, CT, the result of a 1998 arrest for drug-related offense committed about 5 years prior. Smith visited her in prison most every weekend, and wrote about the experience in the NY Times. She wrote a book about the experience, My Year In A Women's Prison.

On January 6, 2006, National Smith Day, Smith co-founded the online SMITH Magazine with Tim Barkow.

Two years later, Smith's book, Not Quite What I Was Planning: Six-Word Memoirs by Writers Famous and Obscure, co-edited by Rachel Fershleiser, was selected as a Top 100 Editors' Pick by Amazon in 2008 and became a New York Times bestseller. Smith and Fershleiser went on to co-edit three more books in the series, including Six-Word Memoirs on Love & Heartbreak, I Can't Keep My Own Secrets: Six-Word Memoirs by Teens Famous & Obscure, and It All Changed in an Instant: More Six-Word Memoirs by Teens Famous & Obscure, all published by Harper Perennial.